Plug board arrangement



ug. 3, 1948. E. l.. KoENlG PLUG vBOARD ABRNGEMENT 2 sheets-shea l` Filed Aug. 22, 1946 H15v ATTORNEY Aug 3, 1948. E. l.. KoENlG 2,446,232

PLUG BOARD ARRANGEMENT Filed Aug. 22, 1946 2 Sheets-Sheet 2 FIGL. 1e'

4 15 2 INVENTOR. U U b El.. Koenig H15 ATTORNEY Patented Aug. 3, 1948 PLUG BOARD ARRANGEMENT Emil L. Koenig Brooklyn. N. Y., assigner to General Railway Signal Company, Rochester,

Application August 22., 1946, Serial No. 692,358

3 Claims. 1

This invention relates .to plug couplers for electrical devices and it more particularly pertains to a plug board having detachable contacts for use in detachably supporting electroresponsive devices.

In a relay and plug board arrangement of the general character disclosed in the patent to J. F. Merkel, Patent No. 2,258,122 dated October 7, 1941, the contact strips-of the plug board are permanently secured in the plug board and thus considerable skill and care is required to attach and solder the wires to the plug board contact strips without burning or otherwise damaging the wires on adjacent contact strips.

An object of the present invention is to improve the method of wiring of the plug board by the use of detachable contact strips that can be suitably secured to the ends of wires before the insertion of the contact strips into their respective slots of the plug board. In this manner the wires can be attached to the plug board contact strips at the most convenient stage in the assembly of the apparatus, such, for example, as immediately after the forming of the wiring harness, without the danger of damaging wires on adjacent contact strips.

Another object of the present invention is to provide a detachable contact strip for the plug board that is self locking upon its insertion from the rear of the board, but that can be manually released from the front of the plug board.

Another object of the present invention is to provide a detachable contact strip for the plug board which is self locking upon its insertion from the rear of the plug board, but that can be manually released from the rear of the plug board to thereby allow the changing of plug board contacts without requiring the removal of the relay.

Another object of the present invention is to limit the flexing of each wire at the point of its connection to a plug board contact strip and protect it vagainst short circuiting with other wires by providing individual recesses in the plug board for such connections, the use oi such recesses being made possible because of the provision for attaching the wires to the contact strips before the insertion of the contact strips into their respective slots in the plug board.

Other objects, purposes, and characteristic features of the present invention will be in part obvious from the accompanying drawings and in part pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to the accompanying drawings in (CL 173-328) 2 v which parts having similar features and iunctions are designated inthe several illustrations by like reference characters. and in which:

Fig. 1 is an elevational view of a relay coupled to its plug board and shown partially in cross section as taken along the line I--i of Fig. 2 and viewed in the direction of the arrows:

Fig. 2 is a back view of the upper portion oi the plug board assembly to which the contacts of the relay shown in Fig. 1 are coupled;

Fig. 3 is an enlarged back view oi a typical plug board connection;

Fig. 4 is a sectional elevational view ofa typical plug and contact strip organization taken along the section line 4 4 o! Fig. 3 and viewed in the direction of the arrows;

Fig. 5 is a plan view of a typical plug and contact strip organization taken along the section line` 5 5 oi Fig. 4 and viewed in the direction of the arrows;

Fig. 6 is a plan view of a typical plug board contact strip during a stage in its development;

Fig. '7 is an elevational view of a typical plug board contact strip:

Fig. 8 is a back view of a plug which is used to provide support for the plug board contact strips:

Fig. 9 is an enlarged back view of a typical modied plug and contact strip organization;

, Fig. 10 is a sectional elevational view of the plug and contact strip organization illustrated in Fig. 9 as taken along the section line Ill-lli of Fig. 9 and viewed in the direction oi the arrows;

Fig. 11 is a plan view of the typical modiiied plug and contact strip organization shown in Fig. 10, taken along the section line H-I i and viewed in the direction of the arrows;

Fig. 12 is a plan view showing one oi the contact strips of Fig. l0 during a stage in its development; and.

Fig. 13 is an elevational view of one of the contact strips employed in the plug and contact organization of Fig. 10.

With reference to Fig, 1, a relay Ris shown as being plug coupled to the plug board PB. The 45 plug board PB is formed of insulating material and it is suitably secured to stationary supports I 0 and il as by thescrew i2 at the top of the plug board, and by the binding posti3 at the bottom of the plug board. The binding post i8 is insulated from the support Il in a suitable manner such as is disclosed specically, for example,

in the above mentioned patent to J. F. Merkel. As is shown in Figs. 1 and 2, the plug board PB provides space for nine pairs of contact strips, although it is to be understood that a greater or lesser number of pairs of contact strips can be provided in accordance with the requirements of practice. The pairs of contact strips are arranged in three vertical rows of three pairs of contact ,strips each. each row being formed by a sub- 4 with the relay contact strips upon the coupling of the relay R to the plug board PB.

It will be noted that when the relay R is couv pled to the plug board PB', the sleeve 28 of that ation with the plug Il, through which the respee-v tive upper and lower contact strips I1 may be i I l Each contact strip I1 is formed preferably of low resistance resilient material, it being blanked out in the form shown in Fig. 6, with the ear or I detent Il protruding from the upper right hand corner as a limit to the extent of insertion of the contact strip I1 into'the plug board PB from the back' of the board. A transverse sleeve Is in which the wire connection tothe contact strip I1 is suitably secured, as by soldering, is formed at the right hand end of the contact strip l1, the

semi-circular notches being formed in the.

ends of the sleeve to conform to the cirmlarA form of the wire. Although only one wire is shown in each sleeve Il, it is to be understood that two wires could -as well be connected, such wires being preferably inserted from the opposite ends of the sleeve II.

After a wire, such as'the wire 2l, is secured to a contact strip I1,l such contact strip is inserted in a slot Il from the back of a plug board PB to a point where the ear il rests against the shoulder 22 within the cavityV 28 which is fonned'of a size and shape as illustrated in Figs. 3, 4 and 5 to receive and house the sleeve Il and a' portion of the insulation at the end ofthe wire 2l. Semi circular'. cavities u of the plug Il (see li'ig.' 8)

cooperate in forming a cylindrical cavity slightly greater in diameter than the' diameter of th insulated wire l I l The contact strip I1 is pierced in a U shaped manner near its center, and an ear is formed upwardly to form a spring detent Il asis shown in Pigs. 6 and l at a point to allow the detent 2l to'snap' back of the shoulder It of the plug board PB when the contact strip I1 is fully inserted in the slot Io from the rear of the plug board PB.

The spring detent Il is depressed in an obvious manner as the contact strip I1 is inserted in the slot II.

The left hand portion Ila of the contact strip relay slides over the rod 2o which is suitably secured to the plug board PB as by the nuts and il. The resilient contact tips 32 of the relay R slide along the plug board contact strips i1 which are supported in position by the wedge-21 of the plug Il. and when the relay R is fully coupled to the plug board PBgthe contact tips 32 oi the relay R bear with suiiicient pressure against the plug board contact strips I1 to insure a dependable low resistance connection. The relay R is l'iaeld in its full plug coupled position by the nut In order to fully appreciate the utility of the removable contact strips as provided by the present invention, some understanding must be had of the manner in which the relays are used in pnctic'e. Among other advantages of vusing plug coupled relays'is the facility of readily changing a relay at times when the contacts fail, or at times when circuit changes are made to modify, or add to. a signalling system that is already in service. i

To facilitate future additions of equipment, relays are generally provided with sparecontacts. and, according to the present invention, wiring connections can be readily-made to spare relay contact strips by the insertion of spare contacts l1 after they have been secured to control wires I1 is formed downwardly at a slight angle (see Fig. '1) to conform to the slope of the wedge shaped portion 21 of the plug I! that protrudes from the-left hand, or front side,- of the plug boardPB as viewed in Pigs. l and 4.

It has been pointed out that the wire 2|, for

` exampe, vis necessarilyy attached to a vcontact `strip' I1 prior to the insertion of such contact strip into a slot il in the plug board PB. When in a manner fully described above; such additions being made without requiring the removal ofthe relay concerned, or without the danger of damaging wires onv adjacent contact strips on that plug board.

If it is required in modification work, or for other reasons, to shift a. wire connection from one plug connection to another, it is necessaryto remove the relayV involved and compress the detent I6 past the edge of the shoulder 26 to allow the contactv strip i1 to be slipped through the slot It and removed from the back of the plug board PB.. Such contact strip I1 can then be inserted in another slot I8 or have other wires attached thereto and reinserted in the same slot as required.

If a pair of relay contacts such as those shown in Fig. l for controlling a signal are damaged and there are spare contacts available on that relay, the signal control wires can be readily moved to connect the spare contacts by simply removing the relay'to allow the depression of the detents Il of the contact strips I1 associated with the relay contacts that are damaged, and then shifting such contact strips I1 to the positions in the plug board PB associated with the spare relay contacts.

If it is desirable in practice to provide the plug board contact strips to be removable from the back of the plug board so that the contact strips can be changed without requiring the removal of the relay, as in shifting a wire from connections the' contact strip Il is fully inserted from the'y back'lof the plug board PBk it is locked in posi- .tion-:bythe 'springing ofthe detent 2l back of .y the shoulder 24|. when the contact strips i1 are l v fully lshown in Fig. 4, they are of suicient, length to extent outwardly from the front o i `tnenlulr'team Pete within a short distance of the front or left-hand end of the plug l, Y II t0 provide-adequate contact surface to engage 'l The contact strip I11 assumes the form shown to one relay contact to another, a contact strip arrangement can be employed such as is shown in Figs. 9, 1o, 1i, 12 and 13.

As is shown in Fig. 9 a deeper opening is' formed in a plug board PBl than is shown for the plug board PB to allow a deeper slot |61 for the contact strip 111 so that a suitable tool such as the blade of a small screw driver can be inserted over the top of the contact strip I11 to release the. lock of the contact strip and allow its removal from the back of the plug board PB1. V

in rig. 12 when it is blanken out during its development, the broadened portion |91 a little to the right of the center forminga semi-circular sleeve when the contact strip is completely' formed as shown in Fig. 13 with notches 201 provided at the ends of the sleeve to conform to the circular form of a wire when it is suitably secured tothe contact strip |1l as by soldering.

The right hand end of the contact strip |11 has a hook 34 formed thereon which extends upwardly when the semi-circular wire connection sleeve is formed in a U-shaped manner as shown in Fig. 13. The contact strip |11 tends to maintain its form as shown in Fig. 13 because of its resiliency. and an additional spring support 35 is provided for urging the hook 34 to its upper position. Such spring 35 can be formed as shown in Figs. l2 and 13 where a U-shaped cutis made in the contact strip |11 when it is, stamped out, and the inner portion of the U forms asupporting spring 35 when the forming of the contact strip is completed as shown in Fig. 13, with the spring 35 being formed downwardly to bear against the lower portion of the contact strip |11 at the point |1b. The left hand portion |1a1 of the .contact strip |11 is formed downwardly at a slight angle as shown in Fig. 13 to conform to the taper of the wedge shaped portion 21 of the plug i5.

Because of the hook 3l being curved slightly to the right, it locks securely behind the shoulder 261, which is similarly shaped, and this particular shape of the hook 34 facilitates the compression of the spring 35 of that conta-ct strip upon the insertion of the contact strip into the slot i 61, from the back of the plug board PB1,

It will be noted that the extra breadth of the sleeve |91 serves as a limit to the extent of the insertion of the contact strip |11 from the back of the plug board PB1 when it engages the shoulder 221 of the plug board PB1, suiiicient depth of insertion being allowed to provide that the hook 3d can slip back of the shoulder 281.

It will be readily apparent from structure described for the contact strip |11 in the plug board PB1 that the wedging of a suitable tool such as the blade of a small screw driver between the contact strip |11 and the upper side of the slot |61 from the back of the plug board is effective to draw the hook 3d away from the shoulder 261, and thereby allow that contact strip to be removed from the back of the plug board by pulling lightly on the wire attached to that cont-act strip without requiring the removal of the relay. The contact strip |11 when removed can of course be inserted in a dierent slot or different wires can be attached to that contact strip for its reinsertion in the same-slot in accord-ance with requirements of practice.

Having described particular plug board contact organizations having detachable contact strips as speciiic embodiment of the present invention, it is desired to -be understood that these forms are selected to facilitate in the disclosure of the invention rather than to limit the numberof forms which the invention may assume, and it vis to be further understood that various adaptations, alterations and modications may be applied to the specic forms shown to meet the requirements of practice, without in lany manner departing from the spirit or scope of the'present invention except as limited by the impending claims.

What I claim is:

1. In a plug coupler of the character described for detachably supporting an electro-responsive device providing quickly detachable electrical connections for a plurality of pairs of contact cured within each o! said openings, said plug` having a taperedl end protruding from the iront of said plug board for spacing said contact tips of each pair, and said plug cooperating with said plug board to form slots extending through said plug board substantially opposite said contact tips, contact strips formed for the attachment of wires at one end thereof, said contact strips being insertable in the respective slots from the back of said plug board after the attachment of wires thereto to an extent that the other end of the strips makes electrical connection with the contact tips of said device, said contact strips being supported at the point of contact with said tips by the protruding portion of the plugs, and said contact strips having formed therein spring detentsadapted to be compressible upon insertion of the contact strips in their respective slots from the backvof the plug board, and adapted to lock said contact strips against backward movement when they are fully inserted from the back of the plug board, whereby the respective contact strips are individually insertable from the back oi the plug board subsequent to the attachment oi' wires thereto aand automatically locked in their insertedpositions, irrespective of whether or not said device is coupled to the front of the plug board at the time of insertion.

2. In a plug coupler providing quickly detachable electrical connections for a plurality of pairs' of spring contact tips of an electro-responsive device, a plug board of insulating material having openings opposite said pairs of contact tips.

'a plug of insulating material secured in each of said openings having a tapered portion extending from the front of the plug board to space the spring contact tips of a pair, said plug cooperating with the plug board to form slots extending through said plug board substantially oppOsite said contact tips, said slots being formed with abutments and with enlarged openings at the back of the plug board, contact strips formed for the attachment of wires at one end insertable with wires attached through the respective slots from the back of the plug board to an extent to make electrical connections at the other end with the respective contact tips and to an extent to cause the Wire connections to the contact strips to enter said enlarged openings, said contact strips having springdetents formed therein so as to engage with said abutments in the respective slots when the contact strips are fully inserted from the back of the plug board, whereby the respective contact strips are individually insertable from the back of the plug board subsequent to the attachment of wires thereto to a position locked against backward movement by engagement of the detents behind the abutment and whereby the respective contact strips when fully inserted have their wire connections enclosed in the portions of the slots at the back of the plug board.

3. In a plug coupler for detachably supporting an electro-responsive device on the front of a plug board to provide quickly detachable electrical connections for a plurality of pairs of spring contact tips arranged in rows on said device, a plug board having openings opposite said pairs of contact tips, a plug of insulating material secured in each of said openings having a tapered portion protruding from the front of the plug board to space the spring contact tips of a pair,

. 7 Y said plus cooaeratlng with said ping board to form slots extendih through said pluzboard substantially Opposite slid contact tips. each slot having a locking abutment formed therein, cm1- tact strips formed for the attachment o! wires at one end insertable with wires attached through saidslots fromthebackoftheplugboard toan extent to make electrical connections at the other end with the respective contact tips, and locking means for locking said contact strips in their fully inserted positions comprising spring detents securedto said contact strips enins said abutments formed in the slots. said detenta being accessible for compression from the back oi the plug board to release the locking of the respective contact strips,V whereby said contactrtrips with wires attached are respectively insertable to a locked position and removable by manual rey lease of the locking from the back of the plug 10i Number `board.irrespectiveorwhetherornotadevlceis ooupledtothetrontotthepluzboard. s MLKOENIG.

REFERENCES CITED The iollowingreferences are of record in the flic of this patent:

UNITED STATES PATENTS y Great Britain July 1s, 1941 

